The present invention relates to a chuck device for holding or fastening thereon a cell for the centrifugation of blood, and the like.
It is known that the centrifugal separation of blood components such as plasma, red and white blood corpuscles and platelets is performed in cells essentially constituted by a rotating container and a stationary coupling to which are connected ducts for the inflow of the blood and the outflow of the separated component intended to be collected. The container comprises an external bell-shaped envelope, normally made of plastic and downwardly closed by a bottom welded thereto, which is caused to rotate by being fixed to a chuck connected to a rotating shaft.
Known chucks, however, have some disadvantageous characteristics, the most evident of which reside in the fact that they are provided with elements for gripping the cell having such a configuration as to exert exclusively radial thrusts. As a consequence of this, inner tensions are developed in the region proximate to the bottom of the container, and more precisely at the welding of the bottom to the bell-shaped envelope, where the maximum stress occurs as a combined effect of the centrifugal force and of the hydrodynamic thrust exerted by the flow of incoming blood. These inner tensions can be so strong as to possibly cause the breakage of the cell, with easily imaginable consequences.
What is described above with reference to the centrifugal separation of blood components is not limited to this field, and similar problems also occur in many other fields.